Issue #10227: Add an allocation cache for a single slice object.
Patch by Stefan Behnel.
diff --git a/Objects/sliceobject.c b/Objects/sliceobject.c
index 2f5c045..c4a1907 100644
--- a/Objects/sliceobject.c
+++ b/Objects/sliceobject.c
@@ -80,19 +80,38 @@
};
-/* Slice object implementation
+/* Slice object implementation */
- start, stop, and step are python objects with None indicating no
+/* Using a cache is very effective since typically only a single slice is
+ * created and then deleted again
+ */
+static PySliceObject *slice_cache = NULL;
+void PySlice_Fini(void)
+{
+ PySliceObject *obj = slice_cache;
+ if (obj != NULL) {
+ slice_cache = NULL;
+ PyObject_Del(obj);
+ }
+}
+
+/* start, stop, and step are python objects with None indicating no
index is present.
*/
PyObject *
PySlice_New(PyObject *start, PyObject *stop, PyObject *step)
{
- PySliceObject *obj = PyObject_New(PySliceObject, &PySlice_Type);
-
- if (obj == NULL)
- return NULL;
+ PySliceObject *obj;
+ if (slice_cache != NULL) {
+ obj = slice_cache;
+ slice_cache = NULL;
+ _Py_NewReference((PyObject *)obj);
+ } else {
+ obj = PyObject_New(PySliceObject, &PySlice_Type);
+ if (obj == NULL)
+ return NULL;
+ }
if (step == NULL) step = Py_None;
Py_INCREF(step);
@@ -260,7 +279,10 @@
Py_DECREF(r->step);
Py_DECREF(r->start);
Py_DECREF(r->stop);
- PyObject_Del(r);
+ if (slice_cache == NULL)
+ slice_cache = r;
+ else
+ PyObject_Del(r);
}
static PyObject *